Mitigation of MHD phenomena in DCLL blankets by Flow Channel Inserts based on a SiC-sandwich material concept

The DCLL blanket is an attractive concept for future fusion reactors. In order to mitigate MHD effects from the interaction between flowing PbLi and magnetic field, Flow Channel Inserts (FCIs) need to be developed. SiC-based materials are main candidates for high-temperature FCIs. In this work, the MHD interactions and their possible mitigation by FCIs consisting of a porous SiC core with a dense protective SiC coating are studied. The dependency between MHD effects and the FCIs’ properties is discussed under relevant conditions for the DCLL concept. The results show that with a porous-dense SiC-sandwich material, a pressure gradient of ∼120 Pa/m is predicted for a 4 T magnetic field, and of ∼300 Pa/m for 10 T, if an FCI with insulating porous core (< ∼1 S/m) is used. Relevant cases considering a PbLi infiltration in the porous SiC core due to possible damages in the protective coating are presented.